Biohacking: what lies behind the term and what has been proven
The essentials at a glance
Biohacking is a collective term without a fixed meaning. We checked with eight institutions, including the Institute for Quality and Efficiency in Health Care, the German Nutrition Society, the Federal Institute for Risk Assessment, and the Robert Koch Institute. None of them uses the term. This is not an objection to the individual practices, but it means that when someone says “biohacking,” they have not yet said anything verifiable.
It only becomes verifiable when looking at the individual methods, and the results vary. Regarding intermittent fasting, the DGE states that there are only a small number of clinical human studies and that their findings are not clear-cut. For caffeine, the BfR gives hard figures in both directions: 400 milligrams per day are considered safe for healthy adults, while 5 to 10 grams of pure caffeine are life-threatening.
First, you will learn where the term comes from and why no institution uses it. This is followed by an overview of six common practices and the evidence for each, then individual chapters on fasting, caffeine, cold, sleep, dietary supplements, and wearables, and finally the question of what can actually be measured in your own body.
What to expect in this article
1. Where the term comes from and what it means
2. Why no institution uses the term
3. Six practices and their evidence base
4. Intermittent fasting: what the DGE says
5. Caffeine in numbers: the upper limit
6. Cold: what the sources actually say
7. Sleep: the best-studied lever
8. Dietary supplements and the stack concept
9. Wearables: what you measure and who can read it
10. What can be measured in your own body
11. Limitations: what this article does not answer
12. What remains of biohacking
Frequently Asked Questions
Sources
Where the term comes from and what it means
Biohacking describes the attempt to deliberately influence your own body and observe the effect. The word comes from software, where a hack is a shortcut that bypasses the intended route. Applied to the body, it suggests control over a process that would otherwise simply run on its own.
The term encompasses almost everything: intermittent fasting, cold showers, dietary supplements, sleep logs, light therapy lamps, rings, and watches with sensors. What these things have in common is not their effect, but the attitude behind them. You try something out and measure what happens.
Key message
Biohacking is an attitude, not a method. That is why the term itself cannot be evaluated; only each individual practice grouped under it can be.
What is new about it and what is not
Going to bed early, drinking less coffee in the evening, eating regularly: These are not inventions of recent years. What is new is the measurement technology worn on the wrist and the language that turns it into a project.
This shift has a side effect that matters for this article. When an uncontroversial recommendation and an unsupported promise appear under the same word, both seem equally well-founded. But they are not equally well-founded, and the difference can be demonstrated.
Three meanings that get conflated
In practice, the word refers to three quite different things. The first meaning is everyday optimization: sleep, diet, exercise, caffeine—everything adjusted and observed in small steps. This is the most harmless and also the most common case.
The second meaning is self-tracking. Here, the focus is not on the intervention but on the number: sleep phases, resting heart rate, step count, recovery metrics. Whatever a sensor provides is measured, and whatever changes the curve is adjusted.
The third meaning is the riskiest and the rarest in Germany. It includes interventions in the body using substances or implants, sometimes outside medical supervision. People who talk about biohacking almost never mean this third level, yet the term includes it nonetheless.
This article therefore comes with a limitation. It covers the first two levels: what people actually do in everyday life. The third level is mentioned only where an institution explicitly warns against something.
Why no institution uses the term
For this article, we specifically searched the organizations that assess health-related claims in Germany: IQWiG, the DGE, the BfR, the RKI, the Federal Centre for Health Education, the consumer advice centers, the WHO, and the MSD Manual. None of these organizations uses the term biohacking in its own publication.
This is not proof that biohacking is harmful or ineffective. It simply means that there is no verified content conveyed by the word. Only the individual components can be examined, and there are statements about those. One of them is representative of the situation.
Documented source
“To date, only a small number of clinical human studies on the effects of intermittent fasting are available, and their findings are inconclusive.”
German Nutrition Society (DGE)
Intermittent fasting, background information, as of 2018
The sentence is revealing because intermittent fasting is the most frequently cited of all biohacking practices. If the evidence is described this way even there, even less can be expected from the less common methods.
Six practices and their evidence
The table compares the six most frequently mentioned practices. The middle column states what an institution actually says about each one; the right-hand column shows what follows from that.
| Practice | What an institution says about it | Classification |
|---|---|---|
| Intermittent fasting | Clinical human studies are few and inconclusive; no studies are available on long-term effects (DGE, 2018) | Open. Neither recommended nor discouraged |
| Caffeine | Up to 400 mg per day for healthy adults without any expected risk; 5 to 10 g in pure form are life-threatening (BfR, 2024 and 2026) | Clear figures in both directions |
| Cold exposure | Hypothermia, frostbite, and chilblains are described; no statement on benefits is provided (MSD Manual, 2024) | Risks demonstrated, benefits not |
| Sleep optimization | Which methods offer the greatest likelihood of success cannot be determined from current research findings (IQWiG, 2024) | Goal undisputed, ranking of methods unclear |
| Dietary supplements | They are not intended to alleviate, cure, or prevent diseases; there are neither approval procedures nor legally defined maximum amounts (consumer advice center, 2025) | Clearly limited by law |
| Wearables | In a study of 24 fitness apps, 19 sent data to third parties (consumer advice center) | No statement on benefits, a clear one on data protection |
The third column is striking. No row contains a clear yes, and none contains a clear no. What it contains are limitations, open questions, and side effects.
Intermittent fasting: what the DGE says about it
The DGE’s technical information is cautious in its wording, for an understandable reason. In addition to the sentence quoted above, it states that clinical studies comparing intermittent and periodic fasting are also lacking.
The distinction becomes clearer when it comes to the time horizon. According to this technical information, no scientific studies are available on the long-term effects of intermittent fasting. Anyone wanting to use a method for years therefore has no data on which to base that decision.
The point at which many summaries go off track
The DGE cites results from animal studies indicating that regular food deprivation may reduce the risk of type 2 diabetes, cardiovascular diseases, neurological diseases, and cancer. These results come from animal studies, and that is exactly how they are presented there.
This qualification disappears in many reproductions. A finding from an animal model becomes a statement about humans. The difference is not cosmetic: it determines whether a statement is supported by evidence or is merely a supposition.
This source also leaves open how intermittent fasting affects mood, physical resilience, cognitive performance, and the risk of eating disorders. The last point deserves attention because rigid eating windows can become problematic in people with a corresponding predisposition.
Two forms that are often lumped together
The DGE distinguishes between intermittent and periodic fasting in its technical information. These refer to different rhythms: in one, eating and fasting phases alternate within a day or a week; in the other, longer fasting phases occur at greater intervals.
Clinical studies comparing these two forms are lacking according to the same source. So anyone who reads that one particular split is superior to the other is not reading a validated statement, but a guess with a number in front of it.
This is not an argument against trying it. It is an argument against the precision that some guides pretend to offer. Setting a time window to the nearest quarter hour suggests a level of precision for which there is no evidence base.
Caffeine in numbers: the upper limit
Caffeine is the most precisely quantified of all the substances discussed here. The BfR gives three figures that should be read together but are usually quoted separately.
Caffeine according to the BfR
200 mg
Single dose at which no health risk is expected for healthy adults – equivalent to 3 mg per kilogram of body weight
400 mg
Daily amount considered safe for healthy adults
5–10 g
pure caffeine is life-threatening – roughly one to two teaspoons
Source: German Federal Institute for Risk Assessment (BfR), Questions and Answers on Caffeine and Caffeinated Foods (as of 2026), and Communication 46/2024 on Caffeine Powder
Why the third number belongs here
The factor between the second and third numbers is twelve to twenty-five. That sounds like a large gap, but it can be bridged quickly in powder form because no volume limits the amount. You cannot accidentally multiply a cup of coffee by twenty, but you can do so with a spoonful of powder.
The BfR documented the case behind this figure: A young woman died after accidentally ingesting around 9 grams of highly concentrated caffeine powder, despite intensive medical treatment. Anyone who uses caffeine as a tool should know this number, not just the 400 milligrams.
The single dose depends on body weight
The 200 milligrams is not a fixed amount for everyone. The BfR gives it together with the basis from which it is derived: 3 milligrams per kilogram of body weight. The 200 therefore applies to a person weighing around 67 kilograms.
Someone weighing 55 kilograms reaches around 165 milligrams per single dose using the same calculation, while someone weighing 90 kilograms reaches around 270. This range is wide enough that a blanket cup count misses the mark.
It is also important to note that the daily amount of 400 milligrams covers all sources combined. Coffee, tea, cola, energy drinks, and caffeine-containing preparations all count toward the total. Anyone who has a caffeinated sports drink in addition to coffee often counts only one of the two sources.
Cold: what the sources actually say
Cold showers and ice baths are among the most visible biohacking practices. We therefore specifically searched what medical reference works say about cold exposure.
The result was one-sided. The MSD Manual discusses cold from the perspective of injury: Cold exposure can cause reduced body temperature and soft-tissue injuries such as chilblains, immersion foot, perniosis, and frostbite. According to it, susceptibility increases due in part to exhaustion, malnutrition, and dehydration.
What Does Not Follow from This
The fact that a reference work lists cold only under injuries is not evidence against cold showers. It means that the search for an institutional statement about benefits came up empty in this case.
For everyday life, the main takeaway is the information about the conditions. According to this source, exhaustion and dehydration increase susceptibility. Taking an ice bath after a hard workout is therefore a different situation from taking a cold shower in the morning.
Sleep: The Best-Studied Lever
Sleep is different from the other topics. No one disputes that sleep matters. What is disputed is how much each measure achieves.
Claim and State of the Evidence
Common Claim
There is an optimal sleep protocol, and anyone who follows the right rules in the right order will sleep measurably better.
What the Reviewed Source Says
The Institute for Quality and Efficiency in Health Care writes about sleep hygiene measures that previous research findings do not allow conclusions to be drawn about which methods are most likely to succeed (2024).
What Follows from This
No ranking of the measures has been established. Anyone who tries a rule and sticks with it because it helps them is acting sensibly. Anyone who presents a particular order as superior is going beyond the available evidence.
The Robert Koch Institute has assessed how common sleep problems are. In an analysis using data from 2024, 16.3 percent of respondents reported difficulty falling asleep and 31.7 percent reported difficulty staying asleep, with higher proportions among women and people with lower educational attainment.
Where Light Therapy Is Proven to Work—and Where It Is Not
Light therapy lamps regularly appear on biohacking lists. There is in fact evidence-based information about them, but it is narrowly limited. IQWiG evaluated 21 randomized controlled trials involving a total of 1,441 adults and found an indication of a short-term benefit compared with placebo.
This analysis concerned the treatment of seasonal depression, which according to the same source affects around 2.5 percent of the population each year. Nothing can be inferred from this for healthy people without this diagnosis. According to the same report, no meaningful study was found on treating this form of depression with vitamin D.
Dietary Supplements and the Stacking Concept
A stack is a combination of several products intended to reinforce one another. We found no assessment of such combinations in any of the sources examined. What does exist are statements about the individual substances and the legal framework.
The consumer advice center summarizes the framework succinctly: Food supplements are foods, and they are not meant to alleviate, cure, or prevent diseases. That is what the law applicable throughout Europe says. Consequently, any advertising claim that establishes a connection to a disease is impermissible, regardless of its effectiveness.
What the market makes of this situation
The Federal Association of Consumer Organizations notes that, to date, there are neither approval procedures nor legally established maximum levels for vitamins or minerals. A product can therefore enter the market without an authority having previously checked its dosage.
According to a survey by the same association, 54 percent of the consumers surveyed had bought at least one food supplement in the past six months, and 95 percent wanted these products to be tested for safety. There is a gap between what is bought and what has been tested.
How to recognize an approved claim
There is one level at which advertising claims are actually verified. Regulation (EU) No. 432/2012 contains a list of approved health claims. What appears there may be put on the packaging; what is missing may not.
These approved claims sound deliberately sober. They say that a nutrient contributes to a normal function. That exact wording is the identifying feature: contributing to something normal is not an improvement beyond normal.
Anything beyond that is marketing language. Statements such as accelerates, optimizes, boosts, or protects against do not appear on any list of approved claims. Anyone who reads them is reading the manufacturer's text, not the result of an assessment.
Wearables: what you measure and who is reading along
Rings, watches, and wristbands are the most visible tools in this scene. We found no assessment of their health benefits from the institutions we examined. We did find one regarding their data practices.
In an investigation of 24 fitness apps, 19 sent data to third parties.
The figure comes from the consumer advice center, which examined 24 fitness apps. Nineteen of them sent data to varying numbers and types of third parties. The same source cites a usage rate of 14 percent among German internet users for wearables.
The blind spot of self-tracking
A sensor on the wrist measures movement, pulse, and skin temperature. Software uses this data to calculate values such as sleep stages or recovery. The measured parameter and the displayed value are therefore not the same thing, and the calculation process in between is usually not disclosed.
In everyday life, this means that a trend over several weeks is more meaningful than a single daily value. Anyone who compares Tuesday's value with Wednesday's is primarily measuring the algorithm's fluctuation as well.
When the number becomes the problem
There is a point at which self-tracking defeats its purpose. Anyone who reads the recovery score first thing in the morning and structures the day around it has reversed the order: The number does not assess how they feel; the number assesses how they feel.
We found no data on how often this pattern occurs among the institutions reviewed, and therefore make no claim about it. What can be said is the logic behind it: An algorithm that translates movement and pulse into a recovery score knows neither about the previous evening nor about the week ahead.
A practical way to handle this is to look at the number only in the evening. Then it stands alongside what the day actually brought, rather than anticipating it. This is not a recommendation from a guideline, but a matter of organization.
What can be measured in your own body
After eight chapters with many open questions, the obvious question is: What can actually be established with confidence? The honest answer separates two levels.
What a laboratory measures are concentrations and markers at a given point in time. What a genetic test reads are variants in genetic information that do not change over the course of a lifetime. Both describe conditions; neither provides instructions for action, let alone a diagnosis.
Predisposition and condition are two different questions
The difference sounds academic, yet it determines how a result should be read. A genetic variant answers the question of how your body fundamentally responds to something. A blood value answers the question of how you are doing with it today.
The first answer never changes. The second can shift within weeks. Anyone who confuses the two levels derives pressure to act from an unchanging predisposition or uses a momentary value to make a statement about their own predisposition.
For self-tracking, this means that a sensor on the wrist operates on a third level: behavior over time. All three levels together provide a picture, but none replaces any of the others.
mybody®x works with a certified specialist laboratory in Germany, performs its analyses in compliance with the GDPR, and has been active since 2016, serving end customers since 2022. The following test represents the genetic level.
DNA test from saliva
Longevity | ALL IN ONE DNA Test
More than 170 gene variants from a saliva sample, analyzed in 74 reports. What the test does not do: It does not diagnose, predict illness, or measure biological age. It describes predispositions, not conditions, and does not replace medical advice.
Product page information, accessed 11/08/2026
One note on how to interpret this belongs here. Genetic testing for medical purposes in Germany is subject to the Genetic Diagnostics Act, which reserves it to physicians and requires informed consent. Anyone wishing to derive a medical decision from a finding needs medical guidance.
Chapter at a glance
Laboratory values are measurable as a snapshot, and genetic variants as lifelong predispositions. Both describe a state and do not prescribe an action. In Germany, medical conclusions are governed by the Genetic Diagnostics Act, which reserves such matters to physicians.
Limitations: what this article does not answer
Nootropics are deliberately not presented as an option in this article. The MSD Manual describes only the risks of amphetamines and notes that high doses can cause life-threatening increases in blood pressure and heart rate. It contains no statement about benefits for healthy people without a medical indication.
We did not find figures on the prevalence of biohacking, the size of the market, or the number of users at any institution. All figures in circulation come from provider or press publications and are therefore not included in this text.
None of the sources reviewed comments on stacks, meaning combinations of multiple supplements. This means neither a warning nor a recommendation can be substantiated, and so neither is included here.
Finally, one limitation regarding this article itself. This article does not assess whether biohacking is worthwhile. It shows where a verified statement exists for individual practices and where it does not. The decision about what someone tries remains their own.
What remains of biohacking
If you take one habit away from this article, let it be this: For every biohacking recommendation, ask about the institution and the year. Not about the study, because studies can be found for almost any claim, but about the body that summarizes the current state of knowledge.
This question sorts things out quickly. For caffeine, a number comes back from the BfR. For intermittent fasting, a statement from the DGE comes back about the lack of clear evidence. For cold exposure, a chapter on frostbite comes back. Three answers, three different situations.
At the beginning was the question of what possibilities biohacking offers. The most reliable answer is unspectacular: The possibilities lie where a practice has a name, a number, and a source. Everything else is an experiment, and an experiment should be called what it is.
Frequently Asked Questions
What does biohacking mean?
Biohacking refers to the attempt to deliberately influence one’s own body and observe the effects. There is no institutional definition: neither IQWiG nor the DGE, BfR, RKI, consumer advice centres, WHO, or the MSD Manual uses the term in its own publications. Therefore, only the individual practices can be assessed, not the term itself.
Is intermittent fasting scientifically proven?
Only to a limited extent. The DGE states that only a small number of clinical human studies on the effects of intermittent fasting are currently available and that their findings are not clear-cut (2018). According to the same source, there are no scientific studies on long-term effects. The frequently cited effects on diabetes, cardiovascular disease, and cancer come from animal studies.
How much caffeine per day is safe?
According to the BfR, no health risk is expected for healthy adults from a single dose of up to 200 milligrams, equivalent to 3 milligrams per kilogram of body weight; up to 400 milligrams per day is considered safe. At the same time, the BfR warns that consuming approximately 5 to 10 grams of pure caffeine is life-threatening.
Do cold showers strengthen the immune system?
The sources reviewed for this article contain no statement on this. The MSD Manual addresses cold exposure exclusively in terms of potential harm and mentions reduced body temperature, chilblains, immersion foot, perniosis, and frostbite (2024). This is not evidence against cold showers, but it is not evidence for them either.
Are food supplements tested before they are sold?
No. The Federation of German Consumer Organisations states that there are still neither approval procedures nor legally defined maximum levels for vitamins or minerals (2025). Legally, food supplements are foods, and they are not supposed to alleviate, cure, or prevent diseases.
Next step
Two questions to ask about every recommendation
Which institution says this, and what year does the statement date from? That is all it takes to put a biohacking recommendation into context. Anyone who wants to see the genetic level in full can find it in the Longevity DNA Test.
To the Longevity DNA Test What is epigenetics?Read more
You might also be interested in this
The level at which lifestyle and genetic information actually intersect.
Why the number of years and the number of healthy years differ so widely.
Sources
- German Nutrition Society (DGE): Intermittent fasting. Technical information, as of 2018 – dge.de
- German Federal Institute for Risk Assessment (BfR): Questions and answers about caffeine and caffeinated foods, including energy drinks, as of 2026, as well as Notice 46/2024 on caffeine powder – bfr.bund.de
- Institute for Quality and Efficiency in Health Care (IQWiG): What to do about sleep problems? As of 2024 – gesundheitsinformation.de
- Consumer advice center: How to use dietary supplements correctly, as of 2025 – verbraucherzentrale.de
The verbatim quote on the state of research, the information about the lack of long-term data, and the note on the origin of the results from animal studies are taken from source [1]. The three caffeine figures and the documented death are taken from [2]. The statement on sleep hygiene comes from [3], and the legal classification of dietary supplements from [4]. Also cited: the analysis of 21 studies involving 1,441 adults on light therapy and the 2.5 percent share for autumn-winter depression from an IQWiG press release (2020); the figures of 16.3 and 31.7 percent for sleep-onset and sleep-maintenance disorders from the Robert Koch Institute’s Journal of Health Monitoring (2024 data); information on cold injuries and amphetamines from the MSD Manual (2024 and 2025); the study of 24 fitness apps and the 14 percent usage rate from a consumer advice center investigation; the figures of 54 and 95 percent from a survey by the Federation of German Consumer Organisations (2025). Information on price, scope, sample type, and laboratory comes from the mybody®x product page, accessed on August 11, 2026. All sources were accessed and verified on August 11, 2026.
mybody®x Editorial & Specialist Team
Laboratory diagnostics Nutritional science Blood test interpretation Nutrigenetics
This article was created by the mybody®x editorial and specialist team. The team combines laboratory diagnostics, nutritional science, and the interpretation of blood analyses. Those who contributed to it are listed on the authors’ page.
Published on March 2, 2024 · Last updated on August 11, 2026
The content is intended for general information and does not replace medical advice, diagnosis, or treatment. Reference ranges depend on the laboratory, method, and age—always follow the information on your report.
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Understanding Longevity: Life Expectancy and Healthy Life Years